﻿#define _CRT_SECURE_NO_WARNINGS 1
#include"stack.h"
//栈的初始化
void STInit(ST* ps)
{
	assert(ps);
	ps->a = NULL;
	ps->top = -1;
	ps->capacity = 0;
}

//栈的销毁
void STDestroy(ST* ps)
{
	assert(ps);
	free(ps->a);
	ps->a = NULL;
	ps->top = -1;
	ps->capacity = 0;
}

//压栈
void STPush(ST* ps, STDataType x)
{
	assert(ps);

	// 
	if (ps->top+1 == ps->capacity)
	{
		int newcapacity = ps->capacity == 0 ? 4 : ps->capacity * 2;
		STDataType* tmp = (STDataType*)realloc(ps->a, newcapacity * sizeof(STDataType));
		if (tmp == NULL)
		{
			perror("realloc fail");
			return;
		}

		
		ps->capacity = newcapacity;
		ps->a = tmp;
	}

	ps->top++;
	ps->a[ps->top] = x;

}
//删除栈顶的数据
void STPop(ST* ps)
{
	assert(ps);
	assert(!STEmpty(ps));
	ps->top--;
}

//取出栈顶数据
STDataType STTop(ST* ps)
{
	assert(ps);
	assert(!STEmpty(ps));

	return ps->a[ps->top];
}

//计算栈的数据个数
int STSize(ST* ps)
{
	assert(ps);

	return ps->top + 1;
}

//判断栈是否是空的
bool STEmpty(ST* ps)
{
	assert(ps);

	return ps->top == -1;
}
